The delivery of air in various parts of a building such as a residence or office building was a relatively easy matter when central heating was first introduced. Simple openings or registers were disposed strategically around the structure to introduce heated air adjacent the floor whereupon the propensity for heated air to rise was utilized to expand the heat throughout the desired area. One or more return ducts were placed at predetermined locations to recapture the air and return the now cooler air to the central unit for reheating.
The advent of central air conditioning somewhat complicated the parameters of the delivery system, especially when common duct work was desired. Now, not only the temperature, but the actual movement patterns and the moisture content of the moving air became important.
As the technology developed, it became more apparent that unless the direction and flow of the air into a given space could be more precisely controlled, the heating/air conditioning system would dictate the positioning of delicate wooden objects such as antique furniture, pianos and the like relative to the flow pattern developed, thereby usurping the homemakers right of choice as to how those items were to be arranged. Moreover, with the increasing popularity of computers and other temperature sensitive electronic appliances in the office place, a need arose to create spots of enhanced temperature control to protect such appliances without subjecting the operators thereof to a hostile human environment.
Through the years a variety of devices have been introduced for the purpose of enhancing the overall comfort and efficiency of heating and cooling systems. Air diffusing registers such as those described by Thomson in U.S. Pat. No. 3,358,577 used air deflector vanes to facilitate air diffusion. Davidson, in U.S. Pat. No. 3,099,949 disclosed an air distributor valve which afforded some control over the direction of flow of the air discharged therefrom which Thomson improved upon in U.S. Pat. No. 3,387,550 when he provided a self-contained valve which permitted the volume of air to be regulated without altering the flow pattern thereof. In 1973, Brown disclosed in U.S. Pat. No. 3,733,995 a new diffuser construction utilizing elongated parallel spaced-apart side walls interconnected by a bridge member having extensions fitting into channels provided therefor in the side walls. More recently, Ohkata, in U.S. Pat. No. 4,497,241, described means for automatically adjusting the angle of a louver pivotally secured in an air passage to manage the direction of flow.
In spite of all of these efforts, a need still exists for a quieter, more energy efficient air distribution device which is especially well suited for spot cooling and spot heating without impairing the nozzle discharge, disrupting the air pattern or altering the discharge characteristics of the air stream.
Moreover, the energy crisis and skyrocketing energy costs gave rise to a need for more efficient spot cooling and the elimination of draftless air diffusion whenever possible. In otherwords, strong economic incentives arose, particularly for industrial managers, to cease cooling areas where cooling was not required while enhancing the creature comfort of those employees whose cooling sensations respond to a draft which evaporates their body moisture.
The present invention is directed to solving the problems of the prior art by providing a readily adjustable, energy efficient, non-turbulent individual air outlet which avoids the noise, inconvenience and energy waste of the prior art devices and can be readily and efficiently controlled to provide a draft spot cooling to preselected locations.